In 1948, the World Health Organization defined health as not only the absence of disease, but also the presence of physical, mental, and social well-being. (Constitution of the World Health Organization. In: World Health Organization, Handbook of Basic Documents. 5th ed. Geneva: Palais des Nations, 3-20 (1952)). The status of a patient's physical, mental, and social functioning is often referred to in the literature as quality-of-life and is used as a measure of health outcome. In the past 25 years, there has been a nearly exponential increase in the evaluation of quality-of-life as a technique of clinical research as a component of determining clinical benefit from an intervention protocol. For example, in 1973, only five articles listed quality-of-life as a key word in the Medline database, whereas in the subsequent four years there were successively 195, 273, 490, and 1,252 such articles. (Testa M A and Simonson D C, N Eng J Med. 334:835-840 (1996). In 1998, approximately 3,724 articles listed quality-of-life as a key word. Thus, the health outcome, or quality-of-life, associated with a clinical intervention has been recognized as an important tool in measuring effectiveness and costs of medical care. (Wilson I B and Cleary P D., JAMA., 273:59-65 (1995)).
Extensive research has resulted in the development of instruments that measure health outcome using quality-of-life tools that follow academically well-established and statistically validated psychometric principles. (Ware J E Jr., J Chronic Dis., 40:473-480 (1987); Spilker B., Quality of Life and Pharmacoeconomics in Clinical Trials, 2nd ed. Philadelphia, Pa.: Lippincott-Raven Co; 1995.) One such tool is the SF-36 (Short form-36), which has been widely used in clinical trials and in clinical practice to assess health outcome. (Clancy C M and Eisenberg J M, Science, 282:245-246 (1998)). The SF-36 was derived from the Medical Outcomes Study, which involved 11,336 patients from 523 different clinical sites. (Ware J E, Sherbourne C D, Davies A R. Developing and testing the MOS 20-item short-form health survey. In: Stewart A L and Ware J E, eds., Measuring functioning and well-being: The Medical Outcomes Study approach. Durham, N.C.: University Press, 277-290 (1992); Ware J E. SF-36 Health Survey: manual and interpretation guide. Boston, Mass.: Nimrod Press; 2:1-3:22 (1993)). The validity and reliability of the SF-36 has been proven in several studies in which researchers tested internal consistency, within subject reliability, and differentiation between patient populations. (McHorney C A, et al., Medical Care, 31:247-263 (1993); McHorney C A, et al., Medical Care, 30:S253-S265 (1992); Jenkinson C, et al., Br Med J, 306:1436-1440 (1993); Brazier J E, et al., Br Med J. 305:160-164 (1992)). The SF-36 has been shown to predict the course of depression during a two-year study, and to be lower overall in patients who experience chronic health disorders. (Wells K B, et al., Archives General Psychiatry, 49:788-794 (1992); Schlenk E A, et al., Quality of Life Res., 7:57-65 (1998)).
The SF-36 is a 36-item questionnaire that assesses eight dimensions of health outcome: physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health. Results from the questionnaire can be reported as a relative number on a scale of 0 to 100, in which 100 is the highest or most functional and 0 is the most compromised for that category of functioning. A summary of the meaning of high and low scores for each category is shown in Table 1.
TABLE 1 Description of Very High and Very Low Scores for the Eight Categories of the MOS SF-36 Questionnaire. SF-36 Interpretation Interpretation Category of a Low Score of a High Score Physical Limited in performing all Performs all types of physical Functioning physical activities activities including the most (PF) including bathing or vigorous without limitations dressing due to health due to health Role- Problems with work or No problems with work or Physical(RP) other daily activities as other daily activities as a a result of physical health result of physical health Bodily Very severe and No pain or limitations due Pain(BP) extremely limiting pain to pain General Evaluates personal health Evaluates personal health as Health(GH) as poor and believes it excellent is likely to get worse Vitality(VT) Feels tired and worn out Feels full of pep and energy all of the time all of the time Social Extreme and frequent Performs normal social Functioning interference with normal activities without interference (SF) social activities due to due to physical or emotional physical or emotional problems problems Role- Problems with work or No problems with work or Emotional other daily activities as other daily activities as a (RE) a result of emotional result of emotional problems problems Mental Feelings of nervousness Feels peaceful, happy, and Health(MH) and depression all of calm all of the time the time
The latter half of the twentieth century has been characterized by an increasing prevalence of chronic disorders. Indeed, seven of the ten leading causes of death in the USA are chronic in nature, accounting for 72% of the deaths from all causes. (National Center for Health Statistics. Health, United States, 1995. Hyattsville, Md.: Public Health Service, 1995.) Chronic disorders such as rheumatic disorders, chronic pain, and fatigue contribute to the 6% of the population that is impaired to some extent in the conduct of major life activities such as work, school, and self-care. (US Department of Health and Human Services, Public Health Service. Healthy People 2000: National Health Promotion and Disease Prevention Objectives. Hyattsville, Md.: Public Health Service; 1991.) Health care use also appears to be substantial for patients with chronic conditions.
In chronic conditions such as rheumatic disorders and chronic pain, biological and physiological factors have an inconsistent relationship to symptoms. (Wilson I B, Cleary P D., JAMA, 273:59-65 (1995)). Therefore, they are difficult to measure by laboratory values. In fact, in clinical practice, anywhere from 30% to 80% of patients who see a physician may have conditions for which no physiological or organic cause is found after routine investigation. (Wilson I B and Cleary P D, JAMA, 273:59-65 (1995)).
In these chronic conditions, pain and fatigue are often suffered over many years without correlation to a diagnosable or definable acute or chronic disease. Therefore, without anatomical or physical correlation, a patient's response to therapy must be monitored by measuring the level of symptoms they report over a period of time. The MOS SF-36 questionnaire is particularly suited to this type of analysis. For example, patients with chronic disorders have been reported to score lower than the norm in several categories of the MOS SF-36, including bodily pain, role-physical, role-emotional, and vitality. See, e.g., Ware J E., SF-36 Health Survey: manual and interpretation guide. Boston, Mass.: Nimrod Press; 2:1-3:22 (1993); Schlenk E A, et al., Health-related quality of life in chronic disorders: a comparison across studies using the MOS SF-36, Quality Life Research, 7:57-65 (1998)).
Although similarities in different categories of the MOS can be observed, data from patients who experience chronic conditions suggests that these patients may show higher variability when analyzing individual MOS categories than with the PCS and MCS summary scores. This variability may result from the frequent coexistence of chronic conditions.
Taking these considerations into accounts, Ware et al. have used principal component analysis on the MOS SF-36 data collected from 2,474 subjects from the US general population to derive summary scores for the eight categories shown above. (Ware J E Jr., Kosinski M, Keller S D. SF-36 Physical & Mental Health Summary Scales: A user's manual. Boston, Mass.: The Health Institute, New England Medical Center; 3:1-4:6 (1994)). The Physical Component Summary (PCS) and Mental Component Summary (MCS) provide two reliable, reproducible scores for the physical and mental health, respectively. The PCS and MCS scores are converted to a scale of 0 to 100, in which 50 is the mean for the US population.
This analysis of the MOS data takes into account the range of symptoms seen with the chronic condition and reduces the variability from individual patient differences. Low scores on the PCS indicate substantial limitations in self care, physical, social, and role activities, severe bodily pain, frequent tiredness, and health generally rated as poor, whereas high scores indicate no physical limitations, high energy level, and health generally rated as excellent. Low scores on the MCS indicate frequent psychological distress, substantial social and role disability due to emotional problems, and/or health generally rated as poor, whereas high scores indicate frequent positive affect and absence of psychological distress and limitations in usual social and role activities. Table 2 shows relative PCS and MCS scores for various chronic health conditions as compared to US population normative data. Standard deviation is abbreviated as S.D.
TABLE 2 Comparison of Physical Component Summary (PCS) and Mental Component Summary (MCS) of the MOS SF-36 Questionnaire. Norms for Number of Mean PCS Mean MCS US Population Respondents Score (sd) Score (sd) Females 1,412 49.07 (10.42) 49.33 (10.32) Males 1,055 51.05 (9.39) 50.73 (9.57) "Healthy" individuals 465 55.26 (5.10) 53.43 (6.33) with no chronic conditions from US population Individuals with self- 881 47.92 (11.62) 43.46 (11.42) reported depression symptoms Individuals with 502 44.96 (12.05) 34.84 (12.17) Clinical Depression Individuals with Arthritis 826 43.15 (11.62) 48.81 (11.11) Individuals reporting 519 43.14 (11.56) 46.88 (11.73) chronic back pain Individuals reporting 818 47.44 (10.81) 48.23 (10.74) allergies Individuals with 214 46.88 (11.49) 46.16 (12.06) dermatitis or chronic skin rash
It has been the experience of the present inventors that many patients with inflammation-related diseases respond with only moderate improvement to dietary programs. Further, this response has been variable, with a large percentage of patients with inflammation-related diseases not responding to dietary changes at all. Pharmaceutical approaches, such as non-steroidal anti-inflammatories or anti-depressants have been used with some success, but many of these drugs carry the risk of undesirable side-effects.
Consequently, there is a need for a dietary supplement and/or medical food that ameliorates at least one of the symptoms, preferably all of the symptoms of an inflammation-related disease, such as arthritis and inflammatory bowel disease. In particular, there is a need for a dietary supplement and/or medical food that improves both the physical and mental functioning of a person suffering from an inflammation-related disease, such as arthritis and inflammatory bowel disease.